Wire-drawing lubricating composition



points of contactwith the apparatus.

'2,94s,ss1

' WIRE-DRAWING LUBRICATING COMPOSITION .Ernest C. Milberger, MapleHeights, and William P.

Kinneman, Jr., Eastlake,-hio, assignors to The Standard Oil Company,Cleveland, @hio, a corporation of 'Ohio No'Drawing. Filed Bot. 25, 1955,Ser. No. 542,771

The present invention relates to an improved wiredra-wing lubricatingemulsion which is particularly useful in connection with the drawing ofcopper Wire and to the composition from which this emulsion is prepared.

Wire is usually manufactured bypulling a rod or heavy wire through aseries of .dies of successively smaller diameter until the desired sizeand finish of wire are obtained. In many cases, the dies are made fromeither Carboloy or diamond and such dies have along-life when not abusedin "use. ln the case of copper wire, the drawing maybe, and frequentlyis, a continuous operation and the wire is drawn through the apparatusat a high speed. The wire is threaded through a number of dies ofsuccessively smaller-size which have capstans, around which thewire'iswrapped, located between each-of the dies in a series. Thesecapstans provide the necessary tension to 1pullthe wire through*the'seriesof dies. Dcpending upon the ultimate size of wire desired, 3,4, 5 or even more die blocks maybe arranged so as to continuously reducethesize of the wire as it passes through the wiredrawing machine.

In a Wire-drawingoperation-it is-customarytoco'ol and lubricate the areaof contact between the die and the wire and between the wire and thecapstan. This is necessary in order to protect the die and therebyprevent it from becoming distorted due to the intense heat engendered bythe wire-drawing operation and also to protect the surface of the wirefromdistortion. One of the methods employed in .a wire-drawing operationfor cooling and lubricating wire-drawing apparatus involves continuouslyspraying a "liquid lubricant on the wire at its various "Many types ofliquid lubricants capable of accomplishing this end with varying successare known to the art. One of the preferred types of liquid lubricant isan aqueous emulsion containing certain ingredients that are known tohave good lubricating and protective properties.

However, it has been difficult to manufacture aqueous emulsions which,in addition to possessing the requisite lubricating and coolingproperties, possess satisfactory stability, i.e., a stability of theemulsion against separation into an aqueous and a non-aqueous layerbetween the time of preparation and the time of use. While the emulsionsare usually prepared in the plant where they are to be used, frequently,because of the size of the batches prepared, the emulsion is allowed tostand for several days or even weeks before it is used. It may alsostand over the week-end when the plant is not operating. It is thereforehighly desirable to the wire-drawing industry that an emulsion of awire-drawing lubricant have good stability during storage. 1

The drawing of copper wire imposes limitations on the composition of thewire-drawing lubricant that are not required of lubricants employed inwire-drawing operations on other metals. For example, one of the commoningredients of compounds used in the preparation of wire-drawingemulsions are the fatty acid soaps. However, compounds which areemployed in the preparation Patented Aug. 9, 1960 of emulsions forcopper wire-drawing operations m'ayiiot have a free fatty acid contentabove 1.0% by "weight. If the free fatty acids in the composition exceedthis limit, amounts of copper soap will be formed which are known tohave an adverse effect on die life, thereby diminis'hing theprofitability of such operation-s. Likewise, compounds containing activesulfur must'b'e avoided as they will produce a stain on the copper wire.

It is the particular object of this invention to provide a compositionthat will readly emulsify with water and thereby provide a solutionwhich will be particularly advantageous for the lubrication and coolingof the dies and wire during a copper wire-drawing operation.

It is another object of this invention to provide a lubricating'compositioncapable of being emulsified with water for-use in acopper"wire-"drawing operation which will possess an unusual degree ofstability between the "time ofrnanufaotureand th'etime of use.

Accordingly, we have formulated a lubricating composition which, whenemulsified with water, will produce an improved lubricant for use indrawing of copper 'wire. In brief, the emulsion-forming compound of thisinvention consists of :a .mixture of a .mineral oil, lard oil, a partialglyceride of a fatty acid, an oil soluble alkali metal petroleum.sulfonate, and .a. glycol monoether.

Themineral oil of-this .inventionmay be any oilder'ived from petroleumfalling withina viscosity range of 50 to 500 SSU measured at F. Themineral oil may be unrefined, or .refined such .as by solvent extractionor acid treatment, as the-economies of the particular situationmaydictate. The-mineral oil serves1principally as .a vehicle'for theother ingredients of this compositionand may be present in amountsranging from about .231) to about 77.5 by weight.

'be present in amounts ranging from 5 to 15% by weight ,of thecomposition, may possess one or two fatty acid radicals of 12 to 18carbon atoms esterified on the "hydroxyl group of glycerol. The fattyacids .may be saturated such as myristic acid or unsaturated "such asoleic acid. Glycerol monolaurate is a preferred example. However, otherpartial glycerides such as glycerol dimyristate or glycerol mono-oleatemay be employed.

The oil soluble petroleum sulfonates useful in the composition of thisinvention are oil-soluble alkali metal petroleum sulfonates having amolecular weight range of 350-650. The alkali metal contained in thesesulfonates is preferably sodium, but lithium or potassium may also beemployed. Sulfonates of the type contemplated herein are known in theart as mahogany acid sulfonates and may be present in amounts rangingfrom 5 to 25% by Weight of the composition. Compositions sold under thetrade-names Hardesty 19 and Carlisle llT are illustrative.

Because of the fact that the lard oil and glyceride of the fatty acidare not compatible and tend to separate in a hydrocarbon vehicle andalso when emulsified with water, an amount of a glycol monoether,varying from 2.5 to 7% by weight of the total composition, is added tothe mixture. The glycol monoether provides a homogeneous solution of theingredients of this composition prior to emulsification and thereafter.The mode of action of the glycol monoether is not known but isunimportant for the purposes of this invention. A number of glycolmonoethers may be employed as stabilizers for facture of copper wire.

this composition, and the preferred glycol may have from 2 to 4 carbonatoms and the alkyl radical of the ether may have 3 to 6 carbon atoms.Two examples of preferred glycol monoethers are ethylene glycolmonobutyl ether and diethylene glycol monobutyl ether.

A minor part of the above composition may be emulsified with a majoramount of water such as in the range of 1 part of the composition to 8to 20 parts of water. Such emulsions are stable over a period of severalweeks.

As the best mode of practicing of our invention, a composition wasprepared containing the following ingredients:

. 56.9 parts by weight of an acid treated mineral oil having a viscosityof 100 SSU at 100 F., 21.8 parts by weight prime lard oil containingless than 1% free fatty acids, 9.1 parts by weight glycerol monolaurate,7.4 parts by weight of oil soluble sodium petroleum sulfonate having amolecular weight of about 350-450 (Hardesty 19), v 4.8 parts by weightof ethylene glycol monobutyl ether.

motor. In the absence of a satisfactory lubricant, rotation of thesheave is accompanied by singing and excessive vibration of the copperwire. Comparison of this test with commercial operations indicated thata composition which passes this test is suitable for commercialwiredrawing.

An emulsion prepared by conventional emulsion techniques from 1 part byweight of the preferred embodiment of this invention and 9 parts byweight of water was applied continuously to the areas of contact betweenthe sheave and the wire in this apparatus. The instant emulsion provedto be entirely satisfactory in this test and eliminated the singing andvibration of the copper wire as the sheave was rotated.

This composition has also proven entirely satisfactory in commercialoperations to persons engaged in the manu- The emulsion was stable forseveral weeks.

Two emulsions were also prepared in accordance with the teachings of thepreferred embodiment of this invention except that the lard oil was leftout of one of the compositions while the glycerol monolaurate wasexcluded from the other. Neither of these compositions provedsatisfactory when tested in the test apparatus described above.Excessive singing and vibration of the copper wire occurred when thesheave was rotated in the presence of these emulsions. Since thecomposition of this invention eliminated all singing and vibration ofthe copper wire, it is believed that there are certain synergisticeffects resulting from the combination of the lard oil and the partialfatty acid glyceride so that an effective lubricant is obtained onlywhen they are combined.

However, the exact theory which explains the effectiveness of thecomposition of this invention is unimportant to the invention. Thisapplication is intended to cover all reasonable modifications of thisinvention falling within the scope of the appended claims.

We claim:

1. A composition consisting of an amount of mineral oil having aviscosity of SSU at 100 F. in the range of about 23 to about 77.5% byweight of the composition, an amount of lard oil in the range of about10 to 30% by weight of the composition, an amount of glycerolmonolaurate in the range of about 5 to about 15% by weight of thecomposition, an amount of an oil soluble alkali metal petroleumsulfonate in the range from about 5 to about 25% by weight of thecomposition, and an amount of ethylene glycol monobutyl ether in therange from about 2.5 to about 7% by weight of the composition.

2. An emulsion consisting of a major amount of water and a minor amountof the composition of claim 1.

References Cited in the file of this patent UNITED STATES PATENTS2,470,913 Bjorksten et a1. May 24, 1949 2,527,889 Moore et al Oct. 31,1950 2,552,913 Waugh May 15, 1951 2,617,769 Nicohls et al. Nov. 11, 19522,632,734 Nunn et a1. Mar. 24, 1953 2,732,345 Kroenig et a1. Jan. 24,1956 2,732,348 Jense et a1. Jan. 24, 1956 2,773,036 Waugh Dec. 4, 1956OTHER REFERENCES Chemicals by Glyco, Glyco Products Co. Inc., Brooklyn,New York, 1944 (Blue Cover) (page 32 pertinent).

Metalworking Lubricants, by Bastian, McGraw-Hill, 1951, p. 69 pertinent.

1. A COMPOSITION CONSISTING OF AN AMOUNT OF MINERAL OIL HAVING AVISCOSITY OF 100 SSU AT 100*F. IN THE RANGE OF ABOUT 23 TO ABOUT 77.5%BY WEIGHT OF THE COMPOSITION, AN AMOUNT OF LARD OIL IN THE RANGE OFABOUT 10 TO 30% BY WEIGHT OF THE COMPOSITION, AN AMOUNT OF GLYCEROLMONOLAURATE IN THE RANGE OF ABOUT 5 TO ABOUT 15% BY WEIGHT OF THECOMPOSITION, AN AMOUNT OF AN OIL SOLUBLE ALKALI METAL PETROLEUMSULFONATE IN THE RANGE FROM ABOUT 5 TO ABOUT 25% BY WEIGHT OF THECOMPOSITION, AND AN AMOUNT OF ETHYLENE GLYCOL MONOBUTYL ETHER IN THERANGE FROM ABOUT 2.5 TO ABOUT 7% BY WEIGHT OF THE COMPOSITION.